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Abstract

The accident potential of a vessel colliding with an offshore platform is significant, concerning both human lives, the environment and financial loss. To quantify and model the risk of collisions in an accurate manner has been a goal of the petroleum industry for years. The COLLIDE risk model became the industry standard about 20 years ago, for calculating the risk of ship collisions against offshore installations on the Norwegian Continental Shelf (NCS). However, the current model does not reflect the technological advances made in navigational equipment, procedures as well as new systems for collision avoidance. Additionally, new modelling theories have been developed which seek to capture the complex socio-technical systems that follows human-machine interactions.

The COLLIDE risk model is currently being revised, in order to account for the new technology that has entered into the vessels and installations. This thesis investigates the current situation for risks and factors relating to vessel-platform collision (allision) on the NCS, with emphasis on the influence of Human and Organizational Factors (HOFs). The main research question was What are the causal factors in allision risk on the NCS, and which HOFs should be addressed to update the current collision risk model?

A literature study was performed, and the collision risk was investigated by using risk analysis methods, taking into account the recent years development of equipment. Based on this, a simple analysis of barriers against collision were performed using the bow-tie method. The analysis included data from reported incidents on the NCS, and found commonalities in the causal factors leading to both actual collisions and a vessel being on a potential collision course.

Although there have been several serious incidents on the NCS, they are too few and scattered to measure overall trends. To assess the HOF s impact on allision risk, it is necessary to gather data on the current operational situation onboard offshore vessels and merchant vessels. In this thesis, this is done with the help of questionnaires handed out to navigating personnel.

The analysis of these questionnaires show that many of the risk-inducing factors known from previous research are valid. One third of the navigators in this thesis survey did not feel that they got enough sleep whilst at sea, most of them because of interruptions on off-duty periods. Sleep deficit is a known factor of human fatigue, and fatigue can cause accidents due to for example reduced reaction time and/or poor situation awareness.

About 35% of the navigators that responded to the survey answered that they feel that their work may suffer from the presence of other personnel on the bridge. Disturbances from people just hanging around seems to be a potential problem for safety. Modern navigators also perform work that are not directly related to navigation. 86% of the navigators answered that they feel they do a lot of other work, and the single most important reason for possibly being inattentive while on duty is paperwork or forms/checklists (44%). Modern smartphones are reportedly also a source of distraction on the bridge, especially in the older age groups (29% in the range 20-40 years and 71% in the ages 40-60). This is something that one would not see just a few years ago, but as the technology advances with increasing speed, the little handheld computer poses a potential new threat to safety.

Further, 76% of the navigators had experienced a near miss in the recent five years, most of them while being offshore. These incidents are almost equally divided between during operations and while sailing . Drug and alcohol abuse offshore is not common, but 32% still reported that they knew of cases of alcohol abuse among navigators the past five years, of which one occasion lead to an incident.

The introduction of improved technologies seems to be widely appreciated among the questioned navigators. However, it was noted that accidents could happen because of incorrect interpretation of data or relying too much on the digital aids, and that this could cause complacency. The high workload and strain from other required duties on board, including much paperwork were also stated to be an issue in causing dangerous situations.

Overall, there also seems to be some inconsistencies in many of the answers. It is likely that there is a degree of underreporting in this survey, even though it was made clear to the people involved that their response to the questionnaires would be completely anonymous. Underreporting is a known problem when trying to quantify causal factors in risk and accident analysis. Eventual further studies should be adjusted accordingly.